• Economic and Environmental Geology
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• v.30 no.6
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• pp.613-624
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• 1997

A study of anisotropy of magnetic susceptibility (AMS) was conducted on the Ordovician-Eocene strata in the Taebaek area. The study area is a northeastern part of the Okchon belt, sometimes called as Paegunsan Synclinal Area. A total of 600 independently oriented samples were collected from 60 sites covering the whole area. With a few exception of late Cretaceous-Eocene volcanic rocks, all the sampled strata are nonmetamorphosed sedimentary rocks, mainly sandstones. Among the 60 sites, 5 sites showed flow lineation lying on the bedding plane, 11 sites showed load foliation parallel to the bedding plane, and 21 sites showed tectonic foliation unrelated to the bedding plane. The tectonic foliations are defined by $k_1-k_2$ ($k_{max}-k_{int}$) anisotropy plane, and are considered as a result of tectonic forces acted perpendicularly to the foliation plane in the geologic past. Regardless of sample-site locations, tectonic force directions defined by $k_3$ ($k_{min}$) axis perpendicular to the tectonic foliation are consistent among the strata of the same geologic age. In the course of geologic time, however, the tectonic force directions showed a clockwise rotation: approximately E-W in the Ordovician sites, NW-SE in the Permian sites, N-S in the Triassic sites, and lastly NE-SW in the late Cretaceous-Eocene sites. The pre-Permian directions showed better clustering in the in-situ (geographic) coordinates, while the younger directions become better clustered after the bedding-tilt correction. It is interpreted that the major tectonic structures of the Taebaek area were controlled by the above-mentioned tectonic forces: The Paegunsan Syncline and the Hambaeksan Fault must have been generated by the NW-SE force of late Permian-early Triassic time. It was then reactivated in the reverse (dextral) sense by the N-S force of Triassic time. The Osipchon Fault in the eastern part of the study area was either generated or reactivated by the NE-SW force of late Cretaceous-Eocene time. The Permo-Triassic NW-SE force should be an expression of the Songnim Disturbance in the Korean peninsula, which is in turn related with the SCB/NCB collision in China.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.3
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• pp.269-286
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• 2015

24-hr integrated $PM_{2.5}$ measurements were performed between December 2013 and October 2014 at an urban site in Gwangju and the collected samples were analyzed for organic carbon (OC), elemental carbon (EC), ionic species, and elemental species. Objectives of this study were to identify $PM_{2.5}$ pollution episodes, to characterize their chemical components, and to examine their probable origins. Over the course of the study period, average $PM_{2.5}$ concentration was $37.7{\pm}23.6$ $(6.0{\sim}121.5){\mu}g/m^3$. Concentrations of secondary ionic species; $NH_4{^+}$, $NO_3{^-}$, and $SO_4{^{2-}}$ was on average $5.54{\mu}g/m^3$ (0.28~ 20.86), $7.60{\mu}g/m^3$ (0.45~ 33.53), and $9.05{\mu}g/m^3$ (0.50~ 34.98), accounting for 13.7% (4.6~ 22.7), 18.6% (2.9~ 44.8), and 22.9% (4.9~ 55.1) of the $PM_{2.5}$ concentration, respectively. Average OC and EC concentrations were $5.22{\mu}g/m^3$ and $1.54{\mu}g/m^3$, taking possession of 4.6 and 22.2% (as organic mass) of the $PM_{2.5}$, respectively. Frequencies at which 24-hr averaged $PM_{2.5}$ exceeded a 24-hr averaged Korean $PM_{2.5}$ standard of $50{\mu}g/m^3$ (termed as an "episode" in this study) were 30, accounting for 21.3% of total 141 measurements. These pollution episodes were mostly associated with haze phenomenon and weak surface wind speed. It is suggested that secondary formation of aerosol was one important formation mechanism of the episodes. The episodes were associated with enhancements of organic mass, $NO_3{^-}$ and $SO_4{^{2-}}$ in winter, of $NO_3{^-}$ and $SO_4{^{2-}}$ in spring, and of $SO_4{^{2-}}$ in summer. Potential source contribution function results indicate also that $PM_{2.5}$ episodes were likely attributed to local and regional haze pollution transported from northeastern China in winter, to atmospheric processing of local emissions rather than long-range transport of air pollutants in spring, and to the $SO_4{^{2-}}$ driven by photochemistry of $SO_2$ in summer.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.92-99
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• 1999

This study was carried out to understand the primary production of biomass, vertical biomass distribution in the stand and the difference of biomass production for part of the trees by stand density for natural Pinus densiflora forest at Mt. Baekdoo located in northeastern China. The primary production of biomass was estimated by the layers of trees, shrubs, herbs for five density classes. For the biomass estimation of the Pinus densiflora trees in stern, stembark and the above-ground tree, the regression model of logW = a + blog(D$^2$H) + c(D$^2$H) was adapted for all of the density classes where W is dry weight, D$_1$ diameter at breast height, and H, tree height. For the biomass estimation in branch and needle, and the needle area, the regression model of logW=a+blogD+cD was adapted for all of the density classes. With increasing stand density the biomass of trees increased but that of shrubs and herbs decreased. Net primary production of biomass in parts of the tree also increased with increasing stand density. However the percentage of the needle biomass among the total biomass in the above-ground tree decreased with increasing stand density. Consequently, primary production rate of biomass in the above-ground tree increased. The primary production of biomass for each part of the trees in natural Pinus densiflora natural forests showed in descending order : stern, needle, branch, and stembark regardless of stand density.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.51-55
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• 2005

Chinese leymus (Leymus chinensis Trin.) is a perennial grass that is widely distributed at high pH sodic and arid soil in the northeastern Asia. An efficient regeneration system was established through somatic embryogenesis of mature seeds to understand its high adaptability to harsh environmental conditions on the basis of molecular biology. The calli were efficiently induced (about $70\%$) from mature seeds on MS medium supplemented with $1.5\;\cal{mg/L}$ 2,4-D. Somatic embryos were formed from the surface of embryogenic callus on MS medium supplemented with $2.0\;\cal{mg/L}\;kinetin\;and\;0.5\;\cal{mg/L}$ NAA after 3 weeks of culture. Roots were induced from the shoot when transferred to MS medium without plant growth regulator for 1 week. Plant regeneration rate was $36\%$ and regenerated plantlets were grown to normal mature plants in pot. An efficient plant regeneration system in this study will be useful for molecular breeding of L. chinensis.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.48-53
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• 2012

The tiger population that once inhabited the Korean peninsula was initially considered a unique subspecies (Panthera tigris coreensis), distinct from the Amur tiger of the Russian Far East (P. t. altaica). However, in the following decades, the population of P. t. coreensis was classified as P. t. altaica and hence forth the two populations have been considered the same subspecies. From an ecological point of view, the classification of the Korean tiger population as P. t. altaica is a plausible conclusion. Historically, there were no major dispersal barriers between the Korean peninsula and the habitat of Amur tigers in Far Eastern Russia and northeastern China that might prevent gene flow, especially for a large carnivore with long-distance dispersal abilities. However, there has yet to be a genetic study to confirm the subspecific status of the Korean tiger. Bone samples from four tigers originally caught in the Korean peninsula were collected from two museums in Japan and the United States. Eight mitochondrial gene fragments were sequenced and compared to previously published tiger subspecies' mtDNA sequences to assess the phylogenetic relationship of the Korean tiger. Three individuals shared an identical haplotype with the Amur tigers. One specimen grouped with Malayan tigers, perhaps due to misidentification or mislabeling of the sample. Our results support the conclusion that the Korean tiger should be classified as P. t. altaica, which has important implications for the conservation and reintroduction of Korean tigers.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.551-560
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• 2018

Bellflower root (Platycodon grandiflorum), which belongs to the Campanulaceae family, is a perennial grass that grows naturally in Korea, northeastern China, and Japan. Bellflower is widely consumed as both food and medicine owing to its high nutritional value and potential therapeutic effects. Since foodborne disease outbreaks often come from vegetables, understanding the public health risk of microorganisms on fresh vegetables is pivotal to predict and prevent foodborne disease outbreaks. We investigated the microbial communities on the bellflower root (n = 10). 16S rRNA gene amplicon sequencing targeting the V6-V9 regions of 16S rRNA genes was conducted via the 454-Titanium platform. The sequence quality was checked and phylogenetic assessments were performed using the RDP classifier implemented in QIIME with a bootstrap cutoff of 80%. Principal coordinate analysis was performed using the weighted Fast UniFrac distance. The average number of sequence reads generated per sample was 67,192 sequences. At the phylum level, bacterial communities from the bellflower root were composed primarily of Proteobacteria, Firmicutes, and Actinobacteria in March and September samples. Genera Serratia, Pseudomonas, and Pantoea comprised more than 54% of the total bellflower root bacteria. Principal coordinate analysis plots demonstrated that the microbial community of bellflower root in March samples was different from those in September samples. Potential pathogenic genera, such as Pantoea, were detected in bellflower root samples. Even though further studies will be required to determine if these species are associated with foodborne illness, our results indicate that the 16S rRNA gene-based sequencing approach can be used to detect pathogenic bacteria on fresh vegetables.

• Geophysics and Geophysical Exploration
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• v.20 no.1
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• pp.12-17
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• 2017

We construct 3D SV-wave velocity structure of the crust and the upper mantle beneath East Asia from Rayleighwave group-velocity measurements. For the construction of the SV-wave velocity model at 10 ~ 100 km depth, we used seismic data recorded at 321 broadband stations in Korea, Japan, and China. Rayleigh-wave group-velocity dispersion curves were obtained by using the multiple filtering technique in the period range from 3 to 150 s. High SV-velocity anomalies are imaged beneath the East Sea from 10 km depth to deeper depth, implying that the Moho beneath the East Sea is between at 10 ~ 20 km depth. We estimated the Moho beneath the Korean peninsula to be around 35 km based on the depth where a high-velocity anomaly is observed. The SV-wave velocity model shows prominent fast S-velocity anomalies near northeastern Japan, associated with the subducting Pacific plate. Low-velocity anomalies are found beneath the east coast of the Korean peninsula at 100 km depth, which may play a role in the formation of the Ulleungdo and the Ulleung basin. We observed low-velocity anomalies beneath the Yamato basin at 100 km depth as well, which may indicate the upwelling of fluid from the Pacific plate via dehydration at deeper depth.

• Journal of the Korean Geographical Society
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• v.29 no.1
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• pp.3-15
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• 1994

The purpose of this study is to investigate the origin of traditional folkhouses of Japan in connection with those of Korea. Japanese folkhouses have received much influence from the Korean Peninsular, mainland China, northern Asia and Southeast Asia. The writer believes that the main stream of folkhouse culture origineted in the Korean Peninsular and flowed into the Japanese Islands. There ara many striking similarities in the folkhouses of Korea and Japan. Firstly, double-row room houses are distributed in the northeastern part of the Korean Penininsular and all parts of the Japanese Islands, and they are classified into the five-room type and four-room type. These types are very similar in both nations in the aspects of and floorplan and distributing patterns. Because floorplan may be used as an indicator of culture regions and cultural diffusion both, nations are believed to be closely related in the interchange of cultures in ancient times. Secondly, stables are allocated to the main house, and they are called "magu" in common "Magu" means horse stable, but there are no horses in it. In ancient times, however, many horses were kept in "magu" in both countries. Thirdly, there are much similarities in the function and structure of the folkhouses of both countries. The characteristics of folkhouses of Japan could be explained as the result of cultural diffusion from the Korean Peninsular.on from the Korean Peninsular.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.1
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• pp.141-148
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• 2007

As Backje(B.C. 18-A.D. 600) is the whole area of Chungcheong, Jeonra, Kangwon and Gyeongsang provinces, the son of the founder of Goguryeo, King Onjoe, making the castle Wu'irae capital of the nation, founded Backje. The capital was transferred to Hansung by B.C. 5 and then to Gongju by A.D. 475. Backje governed the east of China and the northeastern coast. Due to the effect of Chinese culture there are remarkably Chinese cultural elements in dress and its ornament of Baekje. Therefore on the side of cultural part, the noble culture was formed more polished than that of Goguryeo, which affected the culture of dress and ornament. And also there were class differentiation noticeably. Baekje created splendid culture and affected the culture development of Shinra and Japan. The motive of culture creation could be the top of three countries in the foreign trade because there were geographically the widest vast plain and coastline which stretches out from north to south. Although there haven't been many materials about the cultural heritage and records more than other countries, through the modern visual point its design is fresh and more elegant those of other countries. But the fact is that there are few materials related to Baekje. What is worse, there rarely remains all original form and most of them are broken and lost. According1y, we cannot understand not only an original form of Baekje culture and but also the meaning included in it. It goes without saying that there are few materials about the clothes and fabrics. As understanding the culture of Baekje itself is insufficient, a culture enterprise utilizing it - to improve both the added value and economical achievement while combining the latest culture resources with other fields - hasn't been successful. In this study, the purpose is to improve economic power through commercialization and industrialization of the sources of the culture of Baekje. By reanalyzing a form and an image of Baekje relics, it is designed with new motif and modem preference on the condition of our peculiar cultural heritage. And while using this motif with Jacquard pattern, we made it possible to be applied to real life such as interior trinkets, etc.

• Animal cells and systems
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• v.16 no.5
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• pp.408-414
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• 2012

To reexamine taxonomic status of endemic Mogera wogura coreana from Korea, we first obtained partial 12S rRNA sequences (893 bp) and complete cytochrome b gene sequences (1140 bp) of this subspecies, and these sequences and partial cytochrome b sequences (402 bp) were compared to the corresponding haplotypes of M. wogura from East Asia, obtained from GenBank. The one of three 12S rRNA haplotypes in M. w. coreana was identical to one 12S rRNA haplotype of M. w. robusta from East Asia: 10 complete and 13 partial cytochrome b haplotypes of M. w. coreana formed a single clade with one complete and four partial cytochrome b haplotypes of M. w. robusta, respectively. We considered that M. w. coreana from Korea is an endemic subspecies with only morphological differences, although it is necessary to reexamine the subspecies status of M. w. coreana. Additionally, in the 12S rRNA and complete cytochrome b sequences, M. wogura from Japan was distinct from the two continental subspecies of M. w. coreana and M. w. robusta with average distances of 1.76 and 5.65%, respectively; insular M. wogura, with within-group distances of 2.09 and 4.38%, respectively, was also genetically more divergent than the mainland M. wogura, with within-group distances of 0.08 and 0.57%, respectively. Thus, we considered that insular M. wogura of Japan dispersed into neighboring East Asian continent, which is opposite to the traditional hypothesis on the origin of Japanese M. wogura.